Muffin pan



FIG. 1 is a top perspective view of a muffin pan showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a side elevational view thereof.

The ornamental design for a muffin pan, substantially as shown anddescribed.